A new neural-network-based method for structural damage identification in single-layer reticulated shells

Single-layer reticulated shells(SLRSs)find widespread application in the roofs of crucial public structures,such as gymnasiums and exhibition center.In this paper,a new neural-network-based method for structural damage identification in SLRSs is proposed.First,a damage vector index,NDL,that is related only to the damage localization,is proposed for SLRSs,and a damage data set is constructed from NDL data.On the basis of visualization of the NDL damage data set,the structural damaged region locations are identified using convolutional neural networks(CNNs).By cross-dividing the damaged region locations and using parallel CNNs for each regional location,the damaged region locations can be quickly and efficiently identified and the undamaged region locations can be eliminated.Second,a damage vector index,DS,that is related to the damage location and damage degree,is proposed for SLRSs.Based on the damaged region identified previously,a fully connected neural network(FCNN)is constructed to identify the location and damage degree of members.The effectiveness and reliability of the proposed method are verified by considering a numerical case of a spherical SLRS.The calculation results showed that the proposed method can quickly eliminate candidate locations of potential damaged region locations and precisely determine the location and damage degree of members.

A core-shell structured COYID-19 mRNA vaccine with favorable biodistribution pattern and promising immunity

Although inoculation of COVID-19 vaccines has rolled out globally,there is still a critical need for safe and effective vaccines to ensure fair and equitable supply for all countries.Here,we report on the development of a highly efficacious mRNA vaccine,SW0123 that is composed of sequence-modified mRNA encoding the full-length SARS-CoV-2 Spike protein packaged in core-shell structured lipopolyplex(LPP)nanoparticles.SWOT 23 is easy to produce using a large-scale microfluidics-based apparatus.The unique core-shell structured nanoparticle facilitates vaccine uptake and demonstrates a high colloidal stability,and a desirable biodistribution pattern with low liver targeting effect upon intramuscular administration.Extensive evaluations in mice and nonhuman primates revealed strong immunogenicity of SW0123,represented by induction of Th1-polarized T cell responses and high levels of antibodies that were capable of neutralizing not only the wild-type SARS-CoV-2,but also a panel of variants including D614G and N501Y variants.In addition,SW0123 conferred effective protection in both mice and non-human primates upon SARS-CoV-2 challenge.Taken together,SW0123 is a promising vaccine candidate that holds prospects for further evaluation in humans.

N-doped carbon nanofibers arrays as advanced electrodes for supercapacitors

The advancement of supe rcapacitors largely relies on the innovation of electrode materials with high-rate performance and ultra-long cycling stability.In this work,unique N-doped nanofibers on carbon cloth(NCNFs/CC) are prepared by an electrodepositio n-annealing method for application in supercapacitors.The as-prepared N-doped nanofibers(N-CNFs) show diameters of 100-150 nm and cross-link with each other fo rming porous conductive network.Due to enhanced conductivity and reinforced structural stability,the N-CNFs/CC arrays are demonstrated with better electrochemical performance than CNFs/CC counterpart,including higher specific capacitance(195.2 F g^-1 at a current density of 2.5 A g^-1),excellent rate capability(80.5.% capacity retention as the rate increases from 2.5-20 A g^-1) and good cycling stability(99.5.%retention after 10,000 cycles).These reinforced electrochemical properties are attributed to N-doped conductive architecture with faster ion/electron transfer paths and more active sites.Our findings may offe r a new way for construction of advanced high-rate electrodes for energy storage.

Implanting Ni into N-doped puffed carbon: A new advanced electrocatalyst for oxygen evolution reaction

Tailored design and synthesis of high-quality electrocatalysts is vital for the advancement of oxygen evolution reaction(OER).Herein,we report a powerful puffing method to fabricate hierarchical porous N-doped carbon with numerous embedded Ni nanoparticles.Interestingly,during the puffing and annealing process,rice precursor with N and Ni sources can be in-situ converted into Ni-embedded N-doped porous carbon(N-PC/Ni) composite.The obtained N-PC/Ni composite possesses a cross-linked porous architecture containing conductive carbon backbone and active Ni nanoparticles electrocatalysts for OER.The pore formation in N-PC/Ni composite is also proposed because of carbothermic reduction.The N-PC/Ni composite is fully studied as electrocatalysts for OER.Due to increased active surface area,enhanced electronic conductivity and reactivity,the designed N-PC/Ni composite exhibits superior OER performance with a low Tafel slope(~88 mV/dec) and a low overpotential as well as excellent long-term stability in alkaline solution.Our proposed rational design strategy may provide a new way to construct other advanced metal/heteroatom-doped composites for widespread application in electrocatalysis.

Subtle structure tailoring of metal-free triazine luminogens for highly efficient ultralong organic phosphorescence

Ultralong organic phosphorescent materials have invoked considerable attention for their great potential in sensing,data encryption,information anti-counterfeiting and so forth.However,effective ways to achieve highly efficient ultralong organic phosphorescence(UOP)in metal-free organic materials remain a great challenge.Herein,we designed three isomers based on asymmetric triazines with various bromine substituted positions.Impressively,phosphorescence efficiency of p-BrAT in solid state can reach up to 9.7%with a long lifetime of 386 ms,which was one of the highest efficient UOP materials reported so far.Theoretical calculations further demonstrated that para-substitution exhibited the most effective radiative transition for triplet excitons.These results will provide an effective approach to achieving highly efficient UOP materials.